Showing papers in "Mausam in 1977"

Prediction of storm surges on the east coast of India

Abstract: Nomograms to estimate peak storm surges generated by tropical cyclones impinging on, the east coast of India are prepared using Jelesnianski's. SPLASH (1972) model. The. pre-computed nomograms accommodate fixed values for pressure drop, radius of maximum wild, vector motion of storms and offshore bathymetry. Two sets of nomograms are presented -one for the northeast coast of India where the slope of the continental shelf is extremely shallow -the other for the remaining east coast where the slope in general is extremely steep. A nomogram to correct the magnitude of the peak surge for tidal effects is also prepared for the notheast coast of India where the semidiurnal tide range is large. A method to estimate total sea level elevation along a coastal stretch by means of nomograms is given for the northeast coast of India.

Particulate pollution in Delhi due to Indraprastha power plant

Abstract: Particulate deposition in Delhi due to Indraprastha Power Plant within a radius of 15 km from about it are computed employing the long period concentration equation recommended by American Society of Mechanical Engineers. Ten years (1966-75) data of wind speed, wind direction, atmospheric pressure, surface temperature recorded at Safdarjung airport are used for plume rise and concentrations computations. An elaborate computer programme is developed to compute stability, wind and temperature at the stack level, and concentrations and depositions at every 1 km upto 15 km due to each stack.. The total contribution due to the power plant is obtained as a cumulative of the individual stacks. The same procedure is extended in all directions. Isolines delineating zones of low and high deposition are drawn on monthly and annual maps. Zones of high deposition/concentration exceeding U.S. Environmental Protection Agency (EPA) secondary standard located at about 1 km from the power plant oscillates between east and southeast in the year except in monsoon months (June to September) when it lay at a distance of 1 km between west and westnorthwest covering areas like Daryaganj, Ferozshaw Kotla, Irwin Hospital. The total deposition in the winter period is high. The total annual deposition over the area of 15 km radius is 69.864 X 1010 micrograms. Considering the years as a whole the area bounded by the EP A threshold value lies in the southeast between 0 .7 arid 1 .7 km. It is found that in the absence of any background pollution, particulate pollution in the zone under consideration can Le limited to EP A values by increasing the stack levels to 90 metres. With any increase of background pollution the stack height also is to be further raised.

The ball-lightning

Abstract: A theory is considered according to which the ball-lightning is a. high density plasma having an important binding energy exceeding the average thermal translation energy.

Study of a western disturbance

Abstract: The intensification of a western disturbance which moved from central Iran to northwest India from 11 to 13 February 1975 has been studied. It has been shown that the system intensified when a pre-existing surface low over central Iran was overtaken by a strong upper frontal layer from the west, It has also been shown how the strength of this upper frontal layer was maintained during the whole period.

Solar radiation measurements and studies of atmospheric transmission at high altitude stations in India

Abstract: Results of radiation measurements made at high altitude stations in the Himalayas and other locations in India have been studied. The values of direct solar radiation at stations in Kashmir during the pre-monsoon summer months are exceptionally low and lower than those at Kodaikanal in spite of low atmospheric humidity. Such exceptionally low values of direct solar radiation observed in Kashmir have to be attributed to the thick layer of aerosols over most of north India during the summer months. Values of atmospheric turbidity were found to be comparatively high over the Himalayas. Spectral measurements of direct solar radiation as well as global and diffuse solar radiation at the high altitude stations have been discussed.

Correlation of historic climate with historic prices and wages

Abstract: Excursions of average annual air temperature measured by mercury thermometers from 1650 to 1950 show a significant correlation with excursions of annual prices of wheat and a better correlation with wheat prices which have been normalized to the price of sterling to correct for inflation of money. A similar correlation is found between measured air temperatures and the quantity, wages of labour divided by price of wheat, namely the amount of wheat which a labourer's daily wage could buy. The price of wheat normalized in either of these ways correlates fairly well with what is known as historic climate excursions derived from all various climate indicators for the time span from 1250 A.D. to the present. From the price of wheat normalized to the price of sterling, a temperature scale for the last 650 years has been devised for England.

On the application of a primitive equation barotropic Model for the prediction of storm tracks In the Indian region

Abstract: Methods of prediction of storm tracks in the Arabian Sea and the Bay of Bengal by the use of a limited area primitive equation barotropic model have been discussed with case-studies, They are (i) the total flow direct integration method. {ii) the point vortex method in which the basic flow is separated from the disturbance and integrated, treating the vortex as a point and advecting the same at each time step by the basic field and (iii) the modified point vortex method in which the interaction of the disturbance flow with the basic flow is taken into account in the method in (ii).

The Porbandar cyclone of October 1975

Abstract: A severe cyclonic storm formed-over the east central Arabian Sea, from the remnants of an earlier depression over the Bay of Bengal, and crossed north Gujarat coast near Porbandar at 1530 IST On 22 October 1975. This cyclone showed rapid intensification during its formative stages and was singular for its track and, severity. A detailed study of the information, movement and intensity of the storm has been made m this paper on the basis of the synoptic as well as Weather satellite data. It is concluded that the thermal structure of the cyclone and the marked upper tropospheric divergence observational net- were responsible for its rapid intensification.

A comparative study of the summer monsoons over Africa and India

Abstract: A comparative study has been made of the summer monsoons over Africa and India. Important points of similarities and differences between the monsoons over the two regions from the point of their incidence, circulations associated with them and nature of weather have been summarized at the end.

A study of anhysteretic remanent magnetization with the variation of A. C. and D. C. fields on Rajmahal basalts

Abstract: Anhysteretic Remanent Magnetization is produced in a rock specimen when an alternating field, sufficient to cause saturation. is applied and reduced to zero in the presence of a constant direct field. The ARM produced increase with the increase of A. C. field range when the D. C. field is kept constant and reaches a saturation value. The saturation value is different for different specimens and increases as the coercive force increases. The ARM developed in various specimens with the variation of D. C. field, when the maximum alternating field intensity is constant, is a linear function of a small D.C. field.

Simultaneous occurrence of tropical cyclones on either side of the equator in the Indian Ocean area

Abstract: Malurkar (1950) postulated the formation of depressions or cyclones on both Sides of equator within a narrow ( <=40°) longitudinal belt, Pisharoty and Kulkarni (1956) conducted some case studies and Came to the conclusion that they do form as postulated by Malurkar and there is mutual interaction with one another so much so that when one system Intensifies the other weakens, Kuettner (1967) opined that the existence and, alignment of hills in Sumatra are responsible for simultaneous occurrences of storms and depressions on both sides of equator, To verify the above conclusions the present study was undertaken, It covers an 11 year period from 1964 to 1974. During the period as many as 14 storms/depressions formed on both sides of equator. Of course, there were some years when such systems did not develop, They form in transition months with a bias towards the post monsoon season, Kuettner's conclusions are generally supported. Pisharoty and Kulkarni's conclusions could not be supported, by the present study, Malurkar's conclusion that two tropical storms cannot both continue to move westwards and co-exist on either side of the equator when the longitudinal separation is small (<=10°) is also supported.

The impact of weather on the two varieties of winter jowar at Sholapur

Abstract: The paper analyses the relationship between different weather factors like rainfall, minimum and maximum temperatures as independent variables and winter jowar yield as the dependent variable by two methods, namely, (a) the Fisher's technique of regression integral and (b) the selected periods of regression function. For a discontinuous phenomenon such as rainfall at Sholapur, the Fisherian technique seems to be not quite appropriate. The 22-year data analysed was collected at the crop weather station located in Sholapur (Maharashtra). The estimated values of yield by the Fisherian technique applied to the maximum temperature and by the selected periods method as applied to rainfall are found to be quite good in agreement.

Structure of an immature cyclonic storm in the Bay of Bengal as revealed by radar

Abstract: Poorly developed or immature cyclonic storms are common in the Bay of Bengal particularly when their residence time over the sea is short. These often do not exhibit on the radar or satellite pictures all the features normally associated with tropical storms. Spiral rainbands are not stable, a complete eyewall is not formed: false eye circulations develop and probably inhibit intensification. The rainshield area consists of shallow echoes with bright bands while the spiral band and eyewall areas have tall convective clouds probably consisting of supercooled water. Observed features on radar do not give any indication of future motion. The intensity of such immature systems is difficult to assess from observed winds owing perhaps to asymmetry of structure. They are also difficult to locate and track with the available meager synoptic data coastal radar pictures and twice-a-day satellite pictures. A specific case of radar observation of a storm of this type is examined to see how best such storms can be located, tracked and classified.